In recent years, downsizing and increase in packaging density of electronic instruments have advanced rapidly. Adhesive compositions to be used for electronic instruments are required to satisfy various properties, such as adhesiveness, heat resistance and insulation property, because they often remain as adhesives in packages eventually.
Recently, much attention has been put on GaN (gallium nitride) and SiC (silicon carbide) with excellent electrical characteristics instead of silicon (Si) wafers that have heretofore been used as semiconductor elements, and the use of GaN and SiC has increased in the field of a power device and the like. In particular, because of excellent electrical characteristics of SiC, the voltage applied to a unit area of Si becomes higher than that for Si, and along with it, the temperature applied to a unit area also becomes higher. Therefore, an adhesive is also required to have high heat resistance being higher than 150° C., sometimes higher than 200° C., and moreover it is also required to have a long-term high temperature resistance enough for maintaining adhesiveness at that temperature for a long period of time.
It has been disclosed that a tape with an adhesive for TAB and a tape with an adhesive for a lead frame that contain a thermoplastic resin like polyamide, a thermosetting resin like an epoxy resin and a silicone resin in an adhesive layer exert high insulation reliability (see, for example, patent documents 1 and 2). Moreover, an adhesive composition containing an elastomer, a thermosetting component, an inorganic filler, a hardener, and a silicone oligomer has been proposed in order to improve workability or reflow solder heat resistance (see, for example, patent document 3). However, these conventional adhesive compositions had a problem that electrical characteristics and adhesion durability are insufficient under the aforementioned high temperature condition over a long period of time.    Patent document 1: JP 6-256732 A    Patent document 2: JP 6-306338 A    Patent document 3: JP 2006-283002 A